Artificial kidney systems usually include a dialyzer and a dialysis machine which controls the operation of the dialyzer. The dialyzer is used to treat a patient's blood so as to remove water and waste products therefrom. Such dialyzers include a semipermeable membrane which separates the blood and the dialysis solution flowing through the dialyzer. Waste product removal occurs by mass transfer through the membrane, and water removal occurs by ultrafiltration through the membrane.
Some dialysis machines operate to draw the dialysis solution through the dialyzer under a negative pressure (i.e., below atmospheric pressure). These machines normally include: (a) a negative-pressure-type pump positioned downstream of the dialyzer for drawing the dialysis solution from a source through the dialyzer; and (b) adjustable restrictions positioned upstream and downstream of the dialyzer for controlling the flow rate and the negative pressure on the dialysis solution within the dialyzer.
U.S. Pat. No. 3,878,095 Frasier et al discloses a negative-pressure-type dialysis machine of that type. A commercial machine embodying such a system is manufactured and sold by Baxter Travenol Laboratories and is identified as Proportioning Dialyzing Fluid Delivery System (5M 1352-5M 1355).
Two types of negative pressure dialyzers which are commercially available are known as hollow-fiber dialyzers and as capillary-film dialyzers. Each of these dialyzers has two spaced dialysis solution ports and two spaced blood ports. These dialyzers are sold by Baxter Travenol Laboratories as the CF.RTM. hollow-fiber dialyzer and the HD.TM. capillary-film dialyzer.
Presently, during dialysis the dialyzer is supported on a bracket and flexible conduits connect the machine to the dialysis solution inlet and outlet. When the dialysis session is completed, dialysis solution remains in the dialyzer and must be drained. Presently, one technique is to clamp the conduits leading to and from the dialyzer, remove the dialyzer and then drain or discard it. Another technique is to rotate the dialyzer to a horizontal position to minimize leakage and then the operator using her fingers can close the ports and carry the dialyzer to a sink where the dialysis solution can be drained. While somewhat inconvenient, these techniques have been acceptable.
New dialysis machines are becoming commercially available in which the dialyzer is securely and directly connected to the machine without the flexible conduits and with the dialysis solution ports positioned one above the other. At the end of a dialysis session when the dialyzer is disconnected, there is substantial dialysis solution leakage or spillage since there are no hoses to be clamped, and during the removal and horizontal positioning, there is substantial spillage. This result in unacceptable in that the spillage must be cleaned, which is time-consuming, and otherwise generally undesirable.
It is therefore the object of this invention to provide an apparatus and technique for use with the new dialysis machines to permit drainage of the dialyzer after dialysis while preventing spillage.
These and other objects will become apparent from the following description and appended claims.